A system and method for producing pulp for household paper

Abstract

The present invention relates to a pulp production system and method for household paper, the system comprising a hardwood pulper (1) and a softwood pulper (2); the hardwood pulper (1) is connected to a short fiber resin control agent storage tank (3) on its inlet side, and is sequentially connected to a short fiber tapping pre-pulp tank (4) and a short fiber tapping post-pulp tank (5) on its outlet side; the softwood pulper (2) is sequentially connected to a long fiber tapping pre-pulp tank (6) and a long fiber tapping post-pulp tank (7) on its outlet side, the long fiber tapping post-pulp tank (7) is connected to a mixer (8), the mixer (8) is connected to a long fiber resin control agent storage tank (9) and a clean water storage tank (10); the short fiber tapping post-pulp tank (5) and the long fiber tapping post-pulp tank (7) are connected to a mixing tank (11), and the mixing tank (11) is connected to a pulp tank (12). Compared with the prior art, the present invention can avoid the accumulation of resin and also improve the chemical balance of the entire pulp-water system.

Description

Technical Field

[0001] The invention relates to the technical field of pulping and papermaking, and in particular to a pulp production system and method for household paper. Background Art

[0002] Pulp is a fibrous substance made from plant fiber through different processing methods, and can be made into paper after papermaking. The quality of pulp is mainly determined by its fiber morphology and the purity of the fiber. Invention patent CN202011421255.7 discloses a method for producing high-strength and easily dispersible toilet wiping paper. The invention method has a simple process, and the produced paper has good strength and is easy to disperse. However, during the production process, the resin in the slurry is prone to adhesion and deposition, which affects the quality of the product. Summary of the invention

[0003] The object of the present invention is to provide a pulp production system and method for household paper, which can reduce the influence of resin.

[0004] The object of the present invention can be achieved by the following technical solutions: A pulp production system for household paper, comprising a hardwood pulper and a softwood pulper;

[0005] The inlet side of the hardwood pulper is connected to a short fiber resin control agent storage tank, and the outlet side is sequentially connected to a short fiber tapping pre-pulp tank and a short fiber tapping post-pulp tank;

[0006] The outlet side of the softwood pulper is connected in sequence with a long fiber tapping pre-pulp tank and a long fiber tapping post-pulp tank, the long fiber tapping post-pulp tank is connected with a mixer, and the mixer is connected with a long fiber resin control agent storage tank and a clean water storage tank;

[0007] The short fiber tapping pulp pool and the long fiber tapping pulp pool are connected to a mixing pool, and the mixing pools are connected to form a pulp pool.

[0008] Resin control dispersant is added to both the short fiber resin control agent storage tank and the long fiber resin control agent storage tank. The resin control dispersant is one of the important components of the chemicals added in the papermaking system. Its main function is to treat the resin in the slurry, continuously emulsify the anionic resin, disperse and passivate the large particles of resin to prevent re-flocculation, reduce the adhesion of the resin components in pulp and waste paper pulp, and use its own positive charge to effectively adsorb these tiny ions evenly on the fibers and take them away with the fibers, thereby achieving the purpose of no flocculation and no deposition, and preventing the pollution of the net, blanket, drying cylinder and other parts caused by the resin. General resin control agents include talcum powder, aluminum sulfate, surfactants and chelating agents. The preferred resin control dispersant model used in the present invention is DC779F, PH: 7.5, density: 1.03g / cm 3 .

[0009] Preferably, a hardwood control agent pump is provided between the short fiber resin control agent storage tank and the hardwood pulper. Further preferably, the hardwood control agent pump is a metering pump.

[0010] Preferably, a softwood control agent pump is provided between the long fiber resin control agent storage tank and the mixer. Further preferably, the softwood control agent pump is a metering pump.

[0011] Preferably, the mixer is connected to the pulp tank after the staple fiber tapping.

[0012] Preferably, a first switch valve is provided between the mixer and the pulp tank after the staple fiber tapping. More preferably, the first switch valve is connected to a PLC controller.

[0013] Preferably, the mixer is connected to a mixing tank.

[0014] Preferably, a second switch valve is provided between the mixer and the mixing tank. Preferably, the second switch valve is connected to a PLC controller.

[0015] Preferably, the mixer is connected to a pulp tank.

[0016] Preferably, a third switch valve is provided between the mixer and the pulping tank. Preferably, the third switch valve is connected to a PLC controller.

[0017] Preferably, the pulping tank is connected to a wastewater treatment device. Further preferably, the water treated by the wastewater treatment device can be circulated into the clean water storage tank.

[0018] A method for producing pulp for household paper, using the above system to:

[0019] Add the resin control dispersant in the short fiber resin control agent storage tank to the hardwood pulper, and the pulp passes through the short fiber tapping pre-pulp tank and the short fiber tapping post-pulp tank in sequence and then enters the mixing tank;

[0020] The pulp in the softwood pulper passes through the long fiber knocking pre-pulp tank and then enters the long fiber knocking post-pulp tank. The resin control dispersant in the long fiber resin control agent storage tank and the clean water in the clean water storage tank are mixed and diluted in the mixer and then continue to enter the long fiber knocking post-pulp tank. The pulp then enters the mixing tank.

[0021] The pulp coming out of the pulp chest after the short fiber beating and the pulp coming out of the pulp chest after the long fiber beating enter the pulp chest through the mixing chest.

[0022] Preferably, the resin control dispersant in the short fiber resin control agent tank is pumped into the hardwood pulper by a hardwood control agent pump, and the resin control dispersant in the long fiber resin control agent tank is continuously pumped into the mixer by a softwood control agent pump, and the resin control dispersant is mixed and diluted with clean water in the mixer and continuously enters the long fiber tapping pulp tank, and the diluted resin control dispersant is intermittently introduced into the short fiber tapping pulp tank, the mixing tank and the pulping tank by opening and closing the first switch valve, the second switch valve and the third switch valve.

[0023] This pulp production method is the most effective way to control resin.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. The pulp production system of the present invention changes the addition method of the resin control dispersant, which can effectively make the resin finer, and the resin is adsorbed on the fiber surface or stabilized in the pulp system. The fine resin adsorbed on the fiber is taken away by the fiber, thereby avoiding the accumulation of resin on the net, blanket, and pool wall, and also improving the chemical balance of the entire pulp water system;

[0026] 2. The present invention greatly reduces the probability of paper defects such as holes and transparent spots on paper sheets;

[0027] 3. The present invention reduces the cleaning frequency, thereby increasing the product capacity and reducing the production cost (such as pulp consumption, etc.);

[0028] 4. The present invention can continuously add resin to control the dispersant, has good capture, adsorption and passivation effects, can better adjust the zeta potential of the system, and with a certain degree of polymerization, can have good fixation with the fiber after the resin is adsorbed, so that it is fixed on the fiber and taken away with the slurry;

[0029] 5. The system of the present invention can also continuously introduce diluted resin control dispersant into the pulp pool, mixing pool or pulping pool after staple fiber knocking, which can prevent the flocculation of the resin, promote decomposition, and keep the resin in a small particle state. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of a pulp production system for household paper of the present invention;

[0031] In the figure: 1-hardwood pulper, 2-coniferous wood pulper, 3-short fiber resin control agent storage tank, 4-short fiber tapping front pulp tank, 5-short fiber tapping rear pulp tank, 6-long fiber tapping front pulp tank, 7-long fiber tapping rear pulp tank, 8-mixer, 9-long fiber resin control agent storage tank, 10-clean water storage tank, 11-mixing tank, 12-pulping tank, 13-hardwood control agent pump, 14-coniferous wood control agent pump, 15-first switch valve, 16-second switch valve, 17-third switch valve. DETAILED DESCRIPTION

[0032] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following embodiments.

[0033] Comparative Example 1

[0034] A pulp production system for household paper comprises a short fiber resin control agent storage tank 3, a hardwood control agent pump 13, a hardwood pulper 1, a short fiber tapping pre-pulp tank 4, and a short fiber tapping post-pulp tank 5 which are connected in sequence, and a long fiber resin control agent storage tank 9, a softwood control agent pump 14, a softwood pulper 2, a long fiber tapping pre-pulp tank 6, and a long fiber tapping post-pulp tank 7 which are connected in sequence. The short fiber tapping post-pulp tank 5 and the long fiber tapping post-pulp tank 7 are connected to a mixing tank 11, and the mixing tank 11 is connected to a pulping tank 12.

[0035] When using this pulp production system for pulping, the resin control dispersant is pumped into the hardwood pulper 1 and the softwood pulper 2 by the hardwood control agent pump 13 and the softwood control agent pump 14, respectively, and the intake amount is 0.5kg / T paper and 0.3kg / T paper, respectively. After 7-10 days of production, the mesh on the net is adhered by resin particles, the felt cloth is adhered to resin, and there is a thick layer of resin adhered to the pool wall. Increase the intake of the resin control dispersant, 0.5kg / T paper for softwood and 0.8kg / T paper for hardwood. After 7 days of production, there will still be resin adhesion on the wall of the net blanket pool. It affects the quality of the product, and at the same time causes the shutdown for cleaning, resulting in a reduction in production capacity and an increase in cost. Due to the influence of water quality and climate reasons, this addition method often causes resin particles to accumulate in white water and become larger, deposited on the pool wall of the pulp pool, the mesh of the forming network is adhered to, and the felt cloth is sticky, resulting in paper machine paper breaks and paper pages with holes, transparent spots and other paper defects. All these will affect the normal operation of the paper machine and the quality of the product. In the actual production process, this addition method, using the same amount or increasing the amount of dispersant, does not fundamentally solve the resin obstacle.

[0036] Example 1

[0037] A pulp production system for household paper comprises a broadleaf wood pulper 1, a coniferous wood pulper 2, a short fiber resin control agent storage tank 3, a short fiber pre-beating pulp tank 4, a short fiber post-beating pulp tank 5, a long fiber pre-beating pulp tank 6, a long fiber post-beating pulp tank 7, a mixer 8, a long fiber resin control agent storage tank 9, a clean water storage tank 10, a mixing tank 11 and a pulping tank 12.

[0038] The short fiber resin control agent storage tank 3 is connected in sequence to the broadleaf wood pulper 1, the short fiber tapping pre-pulp tank 4, and the short fiber tapping post-pulp tank 5, the coniferous wood pulper 2 is connected in sequence to the long fiber tapping pre-pulp tank 6 and the long fiber tapping post-pulp tank 7, the long fiber tapping post-pulp tank 7 is connected to the mixer 8, the mixer 8 is connected to the long fiber resin control agent storage tank 9 and the clean water storage tank 10, the short fiber tapping post-pulp tank and the long fiber tapping post-pulp tank are both connected to the mixing tank, and the mixing tank is connected to the pulp tank.

[0039] When the system of this embodiment is used for pulp production, the resin control dispersant in the short fiber resin control agent storage tank 3 is added to the hardwood pulper 1, and the resin control dispersant intake is 0.3 kg / T paper. The pulp from the hardwood pulper 1 passes through the short fiber tapping pre-stock tank 4 and the short fiber tapping post-stock tank 5 in sequence and then enters the mixing tank 11;

[0040] The pulp in the conifer pulper 2 passes through the long fiber tapping pre-pulp tank 6 and enters the long fiber tapping post-pulp tank 7. The resin control dispersant in the long fiber resin control agent storage tank 9 and the clean water in the clean water storage tank 10 are mixed and diluted in the mixer 8 and continuously (continuously added for 24 hours) enter the long fiber tapping post-pulp tank 7. The resin control dispersant intake is 0.35 kg / T paper. The pulp coming out of the long fiber tapping post-pulp tank 7 then enters the mixing tank 11.

[0041] The pulp coming out of the pulp chest 5 after the short fiber tapping and the pulp coming out of the pulp chest 7 after the long fiber tapping enter the pulping chest 12 through the mixing chest 11.

[0042] The pulp production system of this embodiment changes the resin control dispersant addition method of the pulp pool 7 after long fiber beating to continuous addition, which has better capture, adsorption and passivation effects, can better adjust the zeta potential of the system, and with a certain degree of polymerization, can have better fixation with the fiber after adsorbing the resin, so that it is fixed on the fiber and taken away with the pulp.

[0043] The present pulp production system and production method can reduce the frequency of cleaning: the addition method of comparative example 1 needs to be shut down for cleaning after 7-10 days, and it takes about 10 hours to clean the system once. The addition method of this embodiment needs to be cleaned after 40-60 days, so it can save about 30-40 hours (calculated based on a 60-day use cycle of a felt cloth), except under normal circumstances. A. Reduced system fiber loss: about 200 kg of pulp fiber remains in the system after shutdown for cleaning. Every time the system is cleaned, 200 kg of pulp fiber is lost. B. Increased production capacity: output calculated based on 60 days: 2.5 tons / hour for machine No. 7 and 3.8 tons / hour for machine No. 8.

[0044] Compared with Comparative Example 1, the cost savings of this embodiment are shown in the following table:

[0045] Cleaning cycle is calculated every 60 days

[0046]

[0047] Example 2

[0048] A pulp production system for household paper, such as Figure 1 As shown, it includes a hardwood pulper 1, a softwood pulper 2, a short fiber resin control agent storage tank 3, a short fiber tapping pre-pulp tank 4, a short fiber tapping post-pulp tank 5, a long fiber tapping pre-pulp tank 6, a long fiber tapping post-pulp tank 7, a mixer 8, a long fiber resin control agent storage tank 9, a clean water storage tank 10, a mixing tank 11, a pulping tank 12, a hardwood control agent pump 13, a softwood control agent pump 14, a first switch valve 15, a second switch valve 16 and a third switch valve 17.

[0049] Among them, the short fiber resin control agent storage tank 3 is sequentially connected with a hardwood control agent pump 13, a hardwood pulper 1, a short fiber tapping pre-stocking tank 4 and a short fiber tapping post-stocking tank 5, the softwood pulper 2 is sequentially connected with a long fiber tapping pre-stocking tank 6 and a long fiber tapping post-stocking tank 7, the long fiber resin control agent storage tank 9 is sequentially connected with a softwood control agent pump 14, a mixer 8 and a long fiber tapping post-stocking tank 7, and the mixer 8 is also connected with a clean water storage tank 10, a short fiber tapping post-stocking tank 5, a mixing tank 11 and a pulping tank 12, a first switch valve 15 is provided between the mixer 8 and the short fiber tapping post-stocking tank 5, a second switch valve 16 is provided between the mixer 8 and the mixing tank 11, and a third switch valve 17 is provided between the mixer 8 and the pulping tank 12. The short fiber tapping post-stocking tank 5 and the long fiber tapping post-stocking tank 7 are connected to the mixing tank 11, the mixing tank 11 is connected to the pulping tank 12, and the pulping tank 12 is connected to a wastewater treatment device.

[0050] When the system of this embodiment is used for pulp production, the resin control dispersant in the short fiber resin control agent storage tank 3 is pumped into the hardwood pulper 1 through the hardwood control agent pump 13, and the resin control dispersant in the long fiber resin control agent storage tank 9 is continuously pumped into the mixer 8 through the softwood control agent pump 14. After the resin control dispersant is mixed and diluted with clean water in the mixer 8, it continuously enters the long fiber tapping pulp tank 7, and the diluted resin control dispersant is intermittently introduced into the short fiber tapping pulp tank 5, the mixing tank 11 and the pulping tank 12 by opening and closing the first switch valve 15, the second switch valve 16 and the third switch valve 17.

[0051] The above description of the embodiments is to facilitate the understanding and use of the present invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A pulp production system for household paper, characterized in that: It comprises a hardwood pulper (1) and a softwood pulper (2); The inlet side of the hardwood pulper (1) is connected to a short fiber resin control agent storage tank (3), and the outlet side is sequentially connected to a short fiber tapping pre-pulp tank (4) and a short fiber tapping post-pulp tank (5); The outlet side of the conifer pulper (2) is connected in sequence to a long fiber tapping pre-pulp tank (6) and a long fiber tapping post-pulp tank (7), the long fiber tapping post-pulp tank (7) is connected to a mixer (8), and the mixer (8) is connected to a long fiber resin control agent storage tank (9) and a clean water storage tank (10); The short fiber tapping pulp pool (5) and the long fiber tapping pulp pool (7) are connected to a mixing pool (11), and the mixing pool (11) is connected to a pulp pool (12).

2. The pulp production system for household paper according to claim 1, characterized in that: A hardwood control agent pump (13) is provided between the short fiber resin control agent storage tank (3) and the hardwood pulper (1).

3. The pulp production system for household paper according to claim 1, characterized in that: A coniferous wood control agent pump (14) is provided between the long fiber resin control agent storage tank (9) and the mixer (8).

4. The pulp production system for household paper according to claim 1, characterized in that: The mixer (8) is connected to the pulp tank (5) after the staple fiber tapping.

5. The pulp production system for household paper according to claim 4, characterized in that: A first switch valve (15) is provided between the mixer (8) and the pulp pool (5) after the staple fiber beating.

6. The pulp production system for household paper according to claim 1, characterized in that: The mixer (8) is connected to a mixing tank (11).

7. The pulp production system for household paper according to claim 6, characterized in that: A second switch valve (16) is provided between the mixer (8) and the mixing tank (11).

8. The pulp production system for household paper according to claim 1, characterized in that: The mixer (8) is connected to a pulping tank (12); the pulping tank (12) is connected to a wastewater treatment device.

9. The pulp production system for household paper according to claim 8, characterized in that: A third switch valve (17) is provided between the mixer (8) and the pulping tank (12).

10. A method for producing pulp for household paper, characterized in that: Using the system as described in any one of claims 1 to 9: Adding the resin control dispersant in the short fiber resin control agent storage tank (3) to the hardwood pulper (1), the pulp passes through the short fiber tapping pre-pulp tank (4) and the short fiber tapping post-pulp tank (5) in sequence and then enters the mixing tank; The pulp in the conifer pulper (2) passes through the long fiber tapping pre-pulp tank (6) and enters the long fiber tapping post-pulp tank (7). The resin control dispersant in the long fiber resin control agent storage tank (9) and the clean water in the clean water storage tank (10) are mixed and diluted in the mixer (8) and then continue to enter the long fiber tapping post-pulp tank (7). The pulp then enters the mixing tank (11); The pulp coming out of the pulp tank (5) after the short fiber tapping and the pulp coming out of the pulp tank (7) after the long fiber tapping enter the pulp tank (12) through the mixing tank (11).

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